In vehicles which have both an internal combustion engine and a further alternative drive, for example an electric drive in the form of electric motors, such vehicles being, for example, vehicles having hybrid drive systems, the driver's propulsion request, which is usually issued by an accelerator pedal and which may be generally referred to as the driver-requested torque FWM, may usually be provided by one of the drives or also by both drives combined. In the latter case, both the internal combustion engine and the alternative drive each provide a partial torque for driving the vehicle, it being possible to set the distribution of partial torques as a function of vehicle states, for example as a function of the charge capacity of the power source which supplies the alternative drive. If the driver requests a higher driving torque than the internal combustion engine is able to provide alone, the alternative drive is additionally connected for a certain period of time in all situations to achieve the driver-requested torque.
Operating the internal combustion engine close to the maximum driving torque or at the maximum possible driving torque (full load) may have a negative impact on consumption, exhaust gas quality, and wear on the engine and drivetrain components. For example, in gasoline engines, in particular in supercharged engines, enrichment must take place at close to full load (lambda<1) to prevent a thermal overload. The enrichment may also be used to boost performance. However, this measure increases consumption and the emission of CO and HC concentrations in the exhaust gas.
In diesel engines, soot emissions increase significantly at full load or close to full load.